Histology Testbank:

1.
What part of the respiratory tree is the functional unit where gas exchange occurs?
a. Alveolar duct
b. Alveoli
c. Alveolar sac
d. Respiratory bronchiole
e. Terminal bronchiole

Answer: b

The respiratory tract is made of branching structures, much like the branches of a tree. The trachea branches into two bronchi which branch into smaller bronchi. The bronchi ultimately branch into smaller bronchioles. Bronchioles are distinguished from bronchi in that they do not have cartilage and submucosal glands. The terminal bronchioles are the last part of the airway in which gas exchange does not occur. Terminal bronchioles lead to the respiratory bronchioles. The respiratory bronchioles are the first section of the respiratory tree that gas exchange can occur. The alveoli duct is analogous to a thoroughfare with many cul-du-sacs branching off of it. At the end of the alveoli duct is an alveoli sac. An alveoli sac is a cluster of alveoli, much like a cluster of grapes. Alveoli are individual sacs where gas exchange occurs.

2.
Which cell type is involved in general sensation of the olfactory mucosa?
a. Basal cells
b. Brush cells
c. Olfactory cells
d. Sustentacular cells
e. All of the above

Answer: b

Olfactory mucosa lines the roof and portions of the walls of the nasal cavity. It contains several cell types: basal cells, brush cells, olfactory cells and sustentacular cells.

Basal cells are located in the basal lamina. Brush cells are involved with general sensation of the olfactory mucosa. Olfactory cells are bipolar neurons that are the receptors for smell. Sustentacular cells are supporting cells. Sustentacular cells are most numerous cell type in the olfactory epithelium.

3.
What type of cells are found in the olfactory mucosa?
a. Basal cells
b. Brush cells
c. Olfactory cells
d. Sustentacular cells
e. All of the above

Answer: e

Olfactory mucosa lines the roof and portions of the walls of the nasal cavity. It contains several cell types: basal cells, brush cells, olfactory cells and sustentacular cells.

Basal cells are located in the basal lamina. Brush cells are involved with general sensation of the olfactory mucosa. Olfactory cells are bipolar neurons that are the receptors for smell. Sustentacular cells are supporting cells. Sustentacular cells are most numerous cell type in the olfactory epithelium.

4.
What type of tissue makes up the rings of the trachea?
a. Compact bone
b. Spongy bone
c. Hyaline cartilage
d. Fibrocartilage
e. Elastic cartilage

Answer: c

The rings of the trachea are composed of hyaline cartilage.

5.
Which cell is a squamous pulmonary epithelial cell?
a. Clara cell
b. Type I pneumocyte
c. Type II pneumocyte
d. Dust cell
e. Brush cell

Answer: b

The Clara cell is found in the terminal bronchioles. The type I pneumocyte is a squamous epithelial cell. It covers most of the surface of the alveoli. The type II pneumocyte is also called a septal cell. The type II pneumocyte secretes surfactant. The dust cell is also called the alveolar phagocyte. Brush cells are occasionally, but rarely, seen in the alveolar epithelium.

6.
Which cell is also called an alveolar phagocyte?
a. Clara cell
b. Type I pneumocyte
c. Type II pneumocyte
d. Dust cell
e. Brush cell

Answer: d

The Clara cell is found in the terminal bronchioles. The type I pneumocyte is a squamous epithelial cell. It covers most of the surface of the alveoli. The type II pneumocyte is also called a septal cell. The type II pneumocyte secretes surfactant. The dust cell is also called the alveolar phagocyte. Brush cells are occasionally, but rarely, seen in the alveolar epithelium.

7.
Which is structure is NOT part of the conducting portion of the airway?
a. Bronchi
b. Larynx
c. Trachea
d. Larynx
e. Respiratory bronchioles

Answer: e

The conducting portion of the airway is where air is moved, warmed and moistened. The nasal cavities, pharynx, larynx, trachea and bronchi are all part of the conducting portion of the airway.

The respiratory portion of the airway is where gas exchange occurs. The respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli are all part of the respiratory portion.

8.
What type of tissue lines the pharynx?
a. Simple squamous epithelium
b. Simple columnar epithelium
c. Stratified squamous epithelium
d. Ciliated pseudostratified epithelium with goblet cells
e. Both c and d

Answer: e

The pharynx is lined by both stratified squamous epithelium and ciliated pseudostratified epithelium with goblet cells. Different regions are lined by a different type of epithelium. Regions of the pharynx that are likely to be roughened up by food are lined by stratified squamous epithelium. Other regions of the pharynx are lined by ciliated pseudostratified epithelium with goblet cells.

9.
What is an olfactory cell?
a. Unipolar neuron
b. Bipolar neuron
c. Multipolar neuron
d. Supporting cell
e. None of the above

Answer: b

An olfactory cell is a bipolar neuron.

10.
Which type of cartilage is found in the larynx?
a. Hyaline cartilage
b. Elastic cartilage
c. Fibrocartilage
d. Both a and b
e. All of the above

Answer: d

The larynx is composed of several cartilages. The thyroid cartilage, cricoid cartilage, arytenoid cartilages, corniculate cartilages and cuneiform cartilages are all composed of hyaline cartilage. The epiglottis is elastic cartilage. There is no fibrocartilage in the larynx.